1. Field of the Invention
The present invention relates to a solid-state image pickup device.
2. Description of the Related Art
A junction field-effect transistor (hereinafter called a “JFET”) is used as a transistor for signal amplification in a pixel of a Complementary Metal-Oxide-Semiconductor (“CMOS”) image sensor, which is a solid-state image pickup device. It is known that, by using a JFET, a signal charge is kept from being caught by an interface state during an amplification operation, whereby noise can be reduced.
In Japanese Patent Laid-Open No. 2004-158508 (hereinafter called “Patent Document 1”), the drain region of a JFET is formed in a region surrounding a photoelectric conversion element, and also serves as an isolation region between neighboring photoelectric conversion elements. The Patent Document 1 refers to disuse of an insulator in the isolation region as a technical advantage.